c# - How to change datagridview cells color dinamically -

i trying change datagridview cells color according value. using code below:

foreach (datagridviewrow item in datagridview1.rows)             {                 int n = item.index;      double hsft = convert.todouble(datagridview1.rows[n].cells[5].value);                 double asft = convert.todouble(datagridview1.rows[n].cells[6].value);                 string ris1 = "1";                 string risx = "x";                 string ris2 = "2";                  if (hsft > asft)                 {                     datagridview1.rows[n].cells[7].value = ris1.tostring();                     datagridview1.rows[n].cells[7].style.backcolor = color.green;                 }                 else if (hsft == asft)                 {                     datagridview1.rows[n].cells[7].value = risx.tostring();                      datagridview1.rows[n].cells[7].style.backcolor = color.yellow;                 }                 else if (hsft < asft)                 {                     datagridview1.rows[n].cells[7].value = ris2.tostring();                      datagridview1.rows[n].cells[7].style.backcolor = color.red;                 } } 

in project works in case it's not working (but don't error). can do?

edit: edited code. check please